While feeding babies, particularly during the first months, feeding must be stopped at intervals in order to expel swallowed air. The problem with bottle feeding, which is well known to parents of infants, is that the bottle feeder must periodically interrupt the infants feeding and return the bottle to its upright position in order to determine the amount of fluid remaining in the bottle. As a result, feeding is needlessly interrupted several times. Such interruptions are, of course, undesirable, particularly since it is often difficult or impossible to get the infant to resume feeding thereafter.
With many baby bottles, the fluid level can only be read in the upright filling position (nipple facing skyward). These bottles have graduated markings on the side of the bottle from the bottom of the bottle that allows the feeder to measure the amount fluid left in the bottle while the bottle is upright.
Other bottles allow the fluid level to be read not only in the filling position but also in the feeding position. In addition to regular filling level markings spaced from the bottom of the bottle, these bottles have feeding level markings which permit the bottle feeder to read the amount of liquid remaining in the bottle during the feeding process without taking the nipple out of the baby's mouth. However, these bottles have a series of ellipses or partial ellipses circumscribing the bottle for indicating the level of the fluid in the bottle when held at predetermined angles. An example of this type of bottle is disclosed in U.S. Pat. No. 5,263,599, issued to Sklar on Nov. 23, 1993, the teachings of which are herein incorporated by reference. The bottle disclosed in this patent is assumed to be held at a low angle to the horizontal early during the feeding when the bottle is mostly full and is gradually raised to a more vertical and fully inverted position as the bottle is emptied. A disadvantage of this bottle is that an assumption is made as to the angle the bottle is held to the horizontal when a certain amount of fluid remains in the bottle. For instance, newborns may have the bottle held longer at a less comfortable and more steep angle to the horizontal, because regurgitation is more likely if any air is ingested. Whereas, an older baby may have a bottle held with the same amount of fluid at a more comfortable and more shallow angle to the horizontal. Further, different feeders hold a baby at different angles depending on the size of the baby and what position is most comfortable for the feeder. As a result, a series of bottles would have to be configured each with a different set of elliptical markings for different feeder and baby size combinations.
Therefore, a need exists for a nursing device, which overcomes the problems discussed above.